Pin-tap lamp socket



April 1953 c. E. GILBERT 2,636,069

PIN-TAP LAMP SOCKET Filed Jan. 4, 1949 INVENTOR 3d .3? CHARLES E. GILBERT ATTO R N EYS Patented Apr. 21, 1953 PIN-TAP LAMP SOCKET Charles E. Gilbert, New York, N. Y.; Margaret Doris Gilbert, Norman Coates, and The Chase National Bank of the City of New York, executors of said Charles E. Gilbert, deceased Application January 4, 1949, Serial No. 69,076

9 Claims. (01. 173-340) The invention relates to lamp sockets adapted to be removably secured to and mounted alon the length of an electrical conductor cord and so that a plurality of electric lights,such as decorative Christmas tree lights, may be displayed along said cord.

One of the objects of the invention is to provide a lamp socket adapted to be removably secured to an electrical conductor cord and which is provided with electrical contact means for making electrical contact with a lamp and also for piercing the insulation of said conductor cord so as to make electrical contact with the wires thereof.

A further object is to provide a lamp socket construction of the above mentioned type which ily secured in place in the socket without the use of tools, and in such manner that they will not only make electrical contact with the Christmas tree lamps but also with the wires of an insulated electrical conductor cord.

A further object is to provide a lamp socket for Christmas tree lamps which may be manu- .iactured at a minimum cost, and of few parts, and in which the electrical contact elements thereof for making contact with the lamp may be rigidly positioned therein and connected in electrical contact with an electrical conductor cord as a step in the assembly of the socket with said cord.

A further object is to provide a lamp socket for Christmas tree and other lamps so constructed that the wires of an insulated electrical conductor cord may be securely and electrically connected with the electrical contact elements of the socket without removing the insulation from said wires.

A further object is to provide a lamp socket for electric light lamps having slots or recesses therein which are adapted to receive and rigidly support a pair or electrical contact blade elements which are adapted to make electrical 2 contact with the base portion of the lamp and with the wires of an insulated electrical conductor cord and without removing the insulation from said conductor cord.

A further object is to provide a lamp socket for electric light lamps having contact blade elements mounted therein adapted to make electrical contact with the base portion of the lamp and also adapted to pierce the insulation of an electrical conductor cord to make electrical contact with the wires of said cord, and also provided with an insulating means for holding the wires of said cord separated from each other when they are assembled with and are in electrical contact with said contact elements.

Various other objects and advantages of the invention will appear more fully hereinafter. The invention consists substantially in the construction, combination, arrangement, and relative location of parts more fully hereinafter set forth and finally pointed out in the appended claims.

In the drawings- Figure l is a side elevation of the lamp socket assembly embodying the invention with a lamp bulb positioned therein, and with parts broken away to indicate the manner in which the electrical contact means of the socket pierce the insulation of an electrical conductor cord;

Figure 2 is an end elevational view of the socket construction showing the conductor cord in place with respect thereto;

Figure 3 is a top plan view of the socket when assembled with a conductor cord;

Figure 4 is a bottom plan view with parts broken away to show the construction and arrangement of the parts;

Figure 5 is a vertical sectional view taken on the line '5-5 of Figure 3 looking in the direction of the arrows;

Figure 6 is a top plan view of the clamping means and of the insulating means for holding the wires of the conductor cord separated from each other when they are in electrical contact with the contact elements of the socket; and

Figures 7 and 8 are side elevational views of the electrical contact elements used in the socket construction.

light lamps.

In the following specification, for purpose of description, I have shown my improved lamp socket as used with the usual Christmas tree It is to be understood however that the invention is not to be limited for such use only, as said sockets are also adaptable for use generally with other types of electric light lamps intended to be mounted along the length of an electrical conductor cord.

Heretofore, with respect to the manufacture of lamp sockets used particularly for Christmas tree electric light lamps which are mounted along the length of an electrical conductor cord, it has been the practice to provide the sockets with a metal cup-shaped shell which is internally threaded to receive the threads of the metallic base portion of the lamp. Before this shell is mounted in the socket the two insulated wires of the electrical conductor cord are cut-and their ends are stripped bare of insulation. Then the bared wire of the cut end of one of the wires is soldered to the base of the shell and the bared Wire of the cut end of the other wire is soldered to the exterior side wall of the shell. The shell is then screwed into Place in the socket on screw threads provided on the interior face thereof and so that it is positioned to receive the threaded base portion of the Christmas tree lamp, or the lamp bulb is merely forced into the socket so that it will have a tight fit with respect thereto and with the metal cup-shaped shell, and so the base portion thereof will make an electrical contact with the soldered wires of the conductor cord through the shell.

This form of construction of socket for Christmas tree lamps; and for other lamps, intended to be mounted along an electrical conductor cord, has proven to be unsatisfactory'for anumber of reasons. In the first place it is a time consuming operation to solder the cut ends of the conductor cord to the shell and then to properly fit the shell in the socket so that it will efliciently receive the base portion of the lamp. Also,as often happens, the Wiresof the conductor cord are not properly soldered to the shell and they become detached therefrom so thatproper electrical contact between the same and the lampwill not be made. Furthermore, the metallic shell usedin this form of construction is comparatively expensive to produce and whenit is screwed into'place or forced into the socket, it oftentimes works loose or it becomes bent or deformed so that the lamp cannot be properly mounted in the socket. Another objection to a string of electrical lamp sockets mounted along an electrical conductor cord, as previously practiced, is that the sockets are fixedly positioned along the cord and their position cannot be changed. nor can they be removed from the cord.

It is the purpose of the present invention to not only simplify the construction of the type of lamp socket heretofore used for Christmas tree lamps, but also to provide a socket construction which may be quickly and detachably secured along an electrical conductor cord and so that the electrical contact elements thereof will be caused to make electrical contact with thewires of said conductor cord without cutting the cord or without removing the insulation thereof and also without soldering the wires to said contact elements.

Referring to the drawing, the socket receptacle construction of the invention consists of five arts, namely, an insulated lamp socket receptacle generally indicated by the letter A; an insulating member 13; a clamping member C; and two electrical contact blades D and E.

The lamp socket receptacle A is more particularly shown in Figures 1, 2, 3 and and comprises a hollow body molded of a suitable insulating material and so that it is provided with the end walls I and 2 and the side walls 3 and 4. The outer faces of the end walls I and 2 are provided with the centrally positioned raised ribs 5 and 5a which extend the length of said walls, and with the projecting top ledges 6 and 1. The outer faces of the side walls 3 and 4 are provided with the outwardly projecting and curved conically shaped portions 8 and 9 which terminate at their top portions in curved outwardly projecting ledges l0 and l I, and with the rounded raised portions l2 and I 3, having the raised ribs I 4, l5, l6 and I1 positioned along the outer side edges thereof. The lower ends of the end walls I and 2 are provided with the rectangular shaped cut-away portions I8, [9, 26 and 2|, positioned on either side of the lower ends of the ribs 5a and 5. The purpose of these cut-away portions will be more fully indicated later on herein.

The lamp socket receptacle is also provided with the usual top opening 22, through which the base of a lamp bulb 23 may be inserted, and with a rectangular shaped opening 24 which extends through the base portion thereof.

The interior faces of the end walls i and 2 of the lamp socket receptacle are formed with grooves or recesses 25 and 26, which extend the length of the receptacle and which are adapted to receive therein the electrical contact blades D and E, which will be described more in detail later on herein. These grooves or recesses are made slightly wider than the width of the contact blades and are of such width that the said contact blades will snugly fit therein. The lower curved portions of the interior faces of the side walls 3 and 4 of the socket receptacle are provided with screw threads 29, as indicated in Figure 5, for receiving the threads on the base of an electric light bulb when it is inserted in the socket. .Said interior faces of the side walls 3 and l have also formed thereon the raised ribs 30 and 3| at their lower ends on the top of which the base of-the light bulb is seated when it is positioned in the socket.

The electrical contact blades D and E are shown more in detail in Figures 5, 7 and 8, and are made by a stamping operation from strips of suitable metallic electrical conducting material. The contact blade D is so formed that it is provided with a long legportion 34 of a width adapted to have a close sliding fit in the groove 25 of the socket receptacle, and with a short leg 35, less in width than the leg '34, and which is stamped out of the metal of leg 34 and bent outwardly at approximately a right angle to said leg 34. The lower end of the leg 34 of contact blade D, is formed with the V-shaped pointed projection 36 which is positioned at one side edge of said leg, and with a projection-3'! at the other side edge which is bent at right angles to the plane of said leg. The short leg 35 is adapted to extend horizontally across the openingin the socket receptacle near the base thereof when said contact blade D is seated in its groove in said socket. The contact blade E is so formed that it is provided with a long leg portion 38 of. a width adapted to have a close sliding fit in the groove 26 of the socket, and with a short leg 39 which is stamped out of the metal of leg 38 and bent outward-1y and at a curving angle to said leg and with its lower end 40 bent inwardly towards leg 38 as indicated more clearly in Figures 5 and 8. The lower end of leg 38 of the contact blade E is provided with a V- shaped pointed projection M at one of its side edges and with the bent projection 42. The purposes of the V-shaped pointed projections 35 and 4| of said contact blades will be more fully exp e ned ere after.

In assembling the contact blades in the socket receptacle the blades are inserted in the grooves '25 and 26 from the bottom of the socket receptacle and so that the V-shaped pointed projection 36 of blade D projects downwardly into the rectangular shaped cut-away portion [8 of the end wall I of the socket receptacle and the b'entprojection 31 engages the bottom edge of the cut away portion [9 of said end wall, and so that the V-shaped pointed projection 4| of blade projects downwardly into the rectangular shaped cut out portion 20 of the end wall 2 of the socket and the bent projection 42 engages the bottom edge of the cut away portion 2| of said end wall. When the blades are thus positioned the V- -shaped projection of contact blade D will be positioned on one side of thebottom opening 24 of the socket and the V-shaped projection of contact blade E will be positioned on the other side of said bottom opening.

When the contact blades D and E are thus positioned in the socket, the said socket is then mounted with respect to the conductor wires 43 and 44 and so that the wire 43 will extend in a groove formed by the rectangular shaped cut away portions t8 and 20 and the ribs and 5a, and the cord 44 will extend in a groove formed by the rectangular shaped cut-away portion 19 and 2| and said ribs 5 and 5a, and so that the V-shaped pointed projection '35 of contact blade D will pierce the insulation of the wire 43, and thus make electrical contact with the conductor thereof, and the V-shaped projection M of contact blade E will pierce the insulation of the wire 44 andmake electrical contact with the conductor thereof.

When the wires of the conductor cord have been positioned with respect to the socket, the insulating member B is then placed in position over the wires 53 and 44 to hold the same in place with respect to the socket. The insulating member B is made of a suitable insulating material, and as shown in Figures 4 and 6, comprises a rectangular shaped body of the same width and length as the rectangular shaped bottom opening 24 in the socket construction. One face of the insulating member B i formed with 2. rectangular shaped flat faced raised portion 46 of such width that its outer side edges 41 and 48 will fit between the inner edges of the lower ends of the side Walls 3 and i of the socket con-strum tion, and the ends of its upper flat face will abut against the lower ends of the ribs 5 and 5a, and the ledges 49 and 50 which are formed around the outer edges of theinsulating member and ad jacent to the side edges 41 and M3 will abut against the lower ends of said sides 3 and 4 of the socket. Centrally positioned. on the upper face of said flat raised portion 46, is a raised rib 50b which extends between the lower ends of ribs 5 and 5a and thus provides a channel on either side of said ribs, when the insulating member B is in position with respect to the socket body, in which the insulated wires of the conductor cord are positioned. The outer face of said insulated memher is formed with a rectangular shaped central depressed portion 50a, the purpose of which will appear hereinafter.

After the insulating member B is placed in position over the insulated wires of the conductor cord, the same is clamped into contact with said wires by the clamping member C. The clamping member is stamped from a suitable resilient metal and formed into a -U -shape and so that it is provided with a base portion 5|, the side legs '52 :and '53, and the bent runner hook iporti'orrs 154.

"and 56. The 'legs -52 and 53 have the tresilient ypron'g member .56 and :51, stamped font of the dica'ted in Figure .2. The :ba'se portion 51 of the clamping member is cut along the lines 151,62, 6:3 and 64 (see Figure .4) and the cut portions :are

bent inwardly *so that they will have a. resilient fitting contact within the depressed :central portion a in the outer face 0f the insulating member B.

In applying the clamping .member .0 to the socket construction, and to "the insulating member B, it is placed so that the cutland bent ,portions of the base thereof will be positioned over the depressed central portion 50a of the outer face of said insulating member and the legs 52 .and53 of the clampingemember will .bepositioned over and along thezside faoesof the sides Band 4 of the socket construction and .so they will lie between the raised ridges .M, l5, l5 and H, on said side faces and with the resilient cut out prongs 58 projecting outwardly from the socket body. The upper bent hook portions 54 and 55 are then snapped over the curved top edges l0 and I of said side walls of thesocket body. The clamping member will thus hold the insulating member B in close contact with the wires of the conductor cord and so that it will presss'aid wires into contact with the V-shaped pointed ends of the contact elements of the socket and "so that .said pointed ends will be caused to pierce the insulation of said conductor cord 'wires W3 and M and make electrical contact with the conductors thereof. The resilient outwardly extending prongs 58 of the clamping member "may then be used to hook the socket construction on a suitable support, such for instance as a branch of a Christmas tree.

'When an electric light lamp is inserted into the assembled socket construction, its screw threaded metal base maybe either screwed into place in the socket bymea'ns of'the screwthreads '29, or the lamp maybe simplyinserted into the socket and it will be sufficiently held in place by means of the saidscrew threads. When the lamp has been fully positioned in the socket, the tip of the base thereof will be in electrical contact with the horizontally extending leg 35 0f the contact blade D and thus establishele'ctrical contact with wire '43 of the conductor cord, and the metallic side or the base of the lamp will be pressedagainst the inwardlyextending leg 39 0f the contact blade and establish electrical contact with the wire 44 of the conductor cord.

From the foregoing it will be seen that I have provided an exceedingly simple and efficient'c'onstruction for electrical sockets adaptable for use with Christmas tree and other types of electric light lamps which is made of a few simple inexpensive parts. Also, the parts of the socket construction may be easily and quickly assembled with little labor and without the use of tools, and may be positioned with respect to an electrical conductor cord without cutting the cord. Furthermore, electrical contact may be made with the wires of the cord through theinsulation thereof and the socket construction permits it to be readily attached to .a branch of a Christmas tree or to any other suitable support after it has been assembled with a conductor cord.

What is claimed is:

1. A lamp socketconstruction comprised of a hollow'socket body having end walls and side walls, the top and bottom thereof being open,

each of said end walls having recesses formed on from each side wall of the recess toward the other side wall thereof and forming a contact-receiving channel with the end wall of the recess, an integral electrical contact positioned in each of the channels of said recesses in said end walls and provided with a pointed end extending downwardly into the cut away portion of said end walls for piercing the insulation of an electrical conductor cord, each of said contacts being formed as a flat strip with its pointed end coplanar therewith, and with a tongue struck out therefrom and adapted to engage a terminal of a lamp bulb base when positioned in said socket, a separable insulating member for holding the insulated wires of an electrical conductor cord in the cut away portions of said end walls and in contact with said pointed ends of said electrical contacts, and a generally U-shaped metallic retaining strip passing across the bottom of said body and said separable member and extending along the sides of said body and having its ends bent over the top edge of said body for clamping the separable insulating member and said conductor cord in position with respect to said socket body and so that the pointed ends of said electrical contacts will pierce the insulation of said conductor cord and make electrical contact with the wires thereof.

2. An electrical socket construction, adapted to be mounted along an insulated conductor cord, comprised of a hollow body made of insulating material and having a pair of vertically extending grooved recesses formed on the interior thereof, each of said recesses having a pair of protruding ribs extending from each side wall of a recess toward the other side wall thereof and forming a contact-receiving channel with the end wall of said recess, electrical contact blade elements seated in said channels, each of said elements being formed as a fiat strip and provided with contacting means for making electrical contact with the base of an electric light lamp and also coplanarly pointed at its lower end to pierce the insulation of the electrical conductor cord to make electrical contact with a wire thereof, a separable insulating member having a rib extending longitudinally thereof for holding the wires of the electrical conductor cord in a separated position with respect to the socket and in contact with the pointed ends of said contact blade elements, and a generally U-shaped metallic clamping strip passing across the bottom of said hollow body and said separable insulating member and along the sides of said body and having its ends bent over the top edges of said body for clamping said insulating member and the electrical conductor cord to said socket and to cause the contact blade piercing means to pierce the insulation of said conductor cord and to hold the same in electrical contact with the wires thereof.

3. An electrical socket receptacle construction, adapted to be mounted along an insulated electrical conductor cord, comprised of a hollow body made of an insulating material and having open top and bottom, a pair of grooved recesses formed on the interior thereof, and screw threads formed adjacent to said grooved recesses, electrical'contact blade elements slidably seated in said recesses, said contact blade elements being provided with pointed piercing ends for piercing the insulation of the electrical conductor cord to make electrical contact with the wires thereof and which extend downwardly through the lower opening of said hollow body, and also with contacting means to make electrical contact with the base of an electric light lamp, a separable insulating member adapted to close the lower opening of said hollow body and having a rib extending therealong for holding the insulated wires of the electrical conductor cord in separated position with respect to the hollow body, and a removable U-shaped metallic clamping member for clamping said insulating member and the electrical conductor cord wires in operative position with said socket and to cause the pointed piercing ends of the contact blade elements to pierce the insulation of said conductor and wires and to hold the same in electrical contact with said wires, said clamping member being formed with a base portion extending over the insulating member, and with side arms extending over the side walls of said socket receptacle and with their free ends engaged over the top edges of the side walls of said socket receptacle.

4. An electrical socket construction comprised of a hollow socket body made of insulating material and provided with end and side walls and open top and bottom, said end walls each having a rectangular shaped cut away portion at its lower end, an outer face having a centrally positioned vertically extending raised rib thereon with its lower end projecting into said cut away portion, and an inner face formed with a vertically extending grooved recess therein, said side walls each having a curved inner face with a plurality of screw threads formed thereon and a raised rib adjacent the bottom thereof forming a seat for the base of an electric light lamp, electrical contact blade elements slidably seated in the grooved recesses in the interior faces of said end walls and provided with contacting means for making electrical contact with the base of an electric light lamp and with piercing points extending from the lower ends thereof which project into the cut away portions at the lower ends of the end walls of the socket, a separable insulating member having a longitudinal rib for holding the insulated wires of an electrical conductor cord in position in the cut away portions of said end Walls of said socket and separated from each other by said longitudinal rib and the lower ends of said raised ribs on the outer face or said end walls and in contact with said pointed ends of said contact blade elements, and a resilient metallic clamping member passing around and clamping said separable insulating member and the electrical conductor cord to the base of said socket and causing said contact blades pointed ends to pierce the insulation of the wires of said conductor cord and to make electrical contact with said wires, said resilient clamping member being of generally U-shape with its base passing across the bottoms of both said body and said separable insulating member and with its sides extending along the sides of said body and its ends bent over the top edges of said body.

5. An electrical socket construction comprised of a hollow socket body made of insulating material and having open top and bottom end and side walls, said end walls each having rectangular shaped cutawayportions at its lower end, anouter face having a centrallyv positioned raised rib thereon with its lower. endprojecting, into said cut away portion, and an inner face formed with a grooved recess therein, saidsidewallseach having a curved inner face with a plurality of screw threads formed thereon, electrical contact blade elements slidably seated in said grooved recesses in said endwallsand adapted to make electrical contact with the base of an electric light lamp, each of saidcontact blade elements also being formed with integral pointed insulatingpiercing means at its lower end which extends downwardly into the cut away portions of said end walls, a separable insulating member having a longitudinal rib for holding thezinsulated. wires of an electrical conductor cord in the cut awayportions of said end walls of thesocket and separated. from, each other by said; longitudinal rib and the lower ends of said raisedribs and in contact withv said pointed piercing means: of said contact blade elements, and a resilientmetal U- shaped means adapted to be detachably applied over said insulating member and the sides of said socket, and to be secured to the top edgeof said socket, saidresilient means comprising a metallic strip havingits base passingacross the bottom of said body and saidsepar-able insulating member and with its sides extending along the sides of said body and with its ends bent over the top edges of said body, to hold said insulated member and the wires of the electrical conductor cord in clamped relation with respect to said socket and so that said pointed piercing means of saidcontact blade elements will pierce the insulation of said conductor cord and make electricalcontact with the wires of said cord.

6. An electrical socket construction comprised of a hollow socket body made of insulating material and formed with end and side walls and open top and bottom, said end walls having rectangular shaped cut away portions at their lower ends and recesses formed on the interior faces thereof, electrical contact blade members seated in said recesses and formed with resilient legs for making electrical contact with the base portion of an electric light lamp and with integral piercing means projecting downwardly into the cut away portions of said end walls for piercing the insulation of an electrical conductor cord to make electrical contact with the wires of said cord, a separable insulating member adapted to be applied to the lower end of said socket body and having a longitudinal rib to hold the insulated Wires of an electrical conductor cord in separated position in said cut away portions of said end walls and in contact with said insulation piercing means of said electrical contact blade members, and means passing around said member and body and comprising a U-shaped metallic strip having its sides extending along the sides of said body with its ends bent over the top edges of said body for clamping said insulating member and electrical conductor cord to said socket body and to cause said insulation piercing means of said electrical contact blades to pierce the insulation of said cord to make electrical contact with the wires of said cord.

7. An electrical socket construction comprised of a hollow socket body made of an insulating material and formed with end and side walls and open top and bottom, said end walls having each rectangular shaped cut away portions at its lower end and a vertically extending recess formed on the interior face thereof, and a vertically cen- 10 trally, extendingl raised rib, on, the exterior face thereof, said side walls having curved inner faces with a plurality of. screw threads formed thereon adapted to cooperate with the threads onthe base of. an electric lightlamp when it is insorted in said socketbody, electrical contactblade members seated. in the recesses formed in said end-walls andprovided with integral contacting means to make electrical contact withthe base of anelectric light lamp and with integral piercing; means onthe lower ends-thereof which proje'ct downwardly into the cut away portions of said end walls: for piercing. the insulation of an electrical conductor. cord to make electrical contact with the wires thereof, a separable insulating member adaptedto be applied to the lower end of saidsocket bodyand having alongitudinal projection to holdthe insulated wires of an electrical conductor cord in separatedposition in' said cut away portions of said end walls and in contact withsaid insulation piercing means of said electrical contact blade members, and a resilient U- shaped' metal member having its base passing across the bottom of saidbody and said separable insulating member with its sides extending along the sides-of said body and its endsbent over the top of said body for holding said insulating member andan electrical conductor cord in position with respect to said socket and to cause said insulating piercing means of the electrical contact blademembers to pierce the insulation of l the wires of said conductor cord;

8. An electrical socket construction comprised of a hollow socket body made of insulating material and formed with a top opening and a bottom opening and end and side walls, said end walls having cut away portions at their lower ends, raised ribs on their outer faces having their lower ends projecting downwardly into said cut away portions, and vertically extending recesses, said side walls having screw threads on the interior faces thereof adapted to cooperate with the threads on the base of an electric light lamp, electric contact blade members seated in the recesses formed in said end walls and provided with means for making electrical contact with the base portion of an electric light lamp, and with means projecting downwardly into said cut away portions of said end walls of said socket body for piercing the insulation of an electrical conductor cord to make electrical contact with the wires thereof, a separable insulting member for holding the insulatin wires of an electrical conductor cord in separated position in said cut away portions of said end walls, and between the lower ends of said raised ribs, and in contact with said insulation piercing means of said contact blade members, said separable insulating member being adapted to close the lower opening of said socket body and formed with an upper face provided with a rectangular shaped raised portion of a width so that its outer side edges will fit between the inner edges of the lower ends of the side walls of said socket, said upper face also having a centrally positioned raised rib thereon adapted to extend between the lower ends of said ribs on the outer faces of said end walls of said socket body to form channels at the base of the socket body between said ribs within which the insulated wires of a conductor cord are positioned, and clamping means comprising a resilient U-shaped metal member for holding said insulating separable member and an electrical conductor cord in position with respect to said 11 socket body and to cause said insulating piercing means of the electrical contact blade members to pierce the insulation of the wires of said conductor cord.

9. As an article of manufacture, a hollow socket body of insulating material for an electrical socket adapted to be mounted along an insulated electrical conductor cord, said body having end and side walls, and an open top and an open bottom, said end Walls having rectangularshaped cut-away portions at their lower ends with an integral projection projecting downwardly into each of said cut-away portions, the lower portions of said side walls and said end Wall projections defining two separated channels adapted to receive the respective wires of a conductor cord, said body also having vertically extending recesses on the inner faces thereof extending the length of said body and adapted to receive electrical contact blade elements, a pair of electrical contact blade elements respectively slidably seated in said recesses and provided with pointed ends for piercing the insulation of an electrical conductor-cord to make electrical contact with the wires thereof, said pointed ends extending downwardly through the open bottom of said body, said contact blade elements also having contacting means to make contact with the base of an electric light lamp bulb, a separable insulating member adapted to close the open bottom of said body and extending between said integral projections for retaining the insulated wires of said electrical conductor-cord, and a U- shaped clamping member formed with a base portion extending over said separable insulating member and with side arms extending over the side walls of said body for clamping said insulat- .12 7 ing member and electrical conductor-cord in op erative position with said body, to cause the ointed ends of said contact blade elements to pierce the insulation of said conductor wires and to hold said ends in electrical contact with said wires.

CHARLES E. GILBERT.

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